| Rhombic night adder | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Suborder: | Serpentes |
| Family: | Viperidae |
| Genus: | Causus |
| Species: | C. rhombeatus |
| Binomial name | |
| Causus rhombeatus (Lichtenstein, 1823) | |
| Synonyms | |
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Causus rhombeatus, commonly known as the rhombic night adder, is a viper species endemic to subsaharan Africa. No subspecies are currently recognized. [2] Like all other vipers, it is venomous.
With an average total length (body + tail) of 60 cm (24 in), this is the largest member of the genus Causus. The longest individual ever recorded was a male, 93 cm (37 in) in total length, collected in eastern Zimbabwe. [3]
The head has a snout that is relatively blunt (i.e., more rounded than in other members of this genus), on the sides of which the nostrils are positioned. The circumorbital ring consists of 2–3 preoculars, 1–2 postoculars, and 1–2 suboculars that separate the eye from the supralabials. The temporal scales usually number 2+3, sometimes 2+4, but very rarely 2+2 or 3+3. There are 6 supralabial scales, very rarely 7. The sublabial scales usually number 7 or 10, rarely 8, and very rarely 11, 12 or 13. The first 3–4 sublabials are in contact with the anterior chin shields. The posterior chin shields are small and often indistinguishable from the gulars. [3]
At midbody there are 15–21 rows of dorsal scales that are moderately keeled and have a satiny texture. The ventral scales number 120–166, the subcaudals, most of which are divided, 15–36. [3]
The color pattern consists of a ground color that is usually some shade of brown (possibly pinkish or grayish-brown), but occasionally olive green. This is overlaid with a pattern of 20–30 rhombic blotches that have pale edges, as well as a sprinkling of black scales and oblique black bars on the sides. [4] Each oblique black bar is topped by one or two black spots, each with a pale centre, and strongly resembling an eye. Northern populations may be patternless, [3] making them difficult to identify, while in others the pale edges may be missing, the rhombic blotches may be a darker color, or there may even be a dark brown vertebral stripe. The head has a characteristic V-shaped mark that may be solid black, or brown with a black outline. [4] Compare this with the description of the common egg-eater Dasypeltis scabra , a species that has a colour pattern and behaviour that may be an evolutionary strategy for defensive mimicry.
Rhombic night adder, [3] [4] demon night adder, Cape night adder, [5] African night adder, Cape viper. [6]
Savannas of subsaharan Africa from Nigeria east to Sudan, Ethiopia, Somalia and Kenya, south through Tanzania, Uganda, Rwanda, Burundi, DR Congo, Angola, Zambia, Malawi, Zimbabwe, northern Botswana, Mozambique, Eswatini, and eastern South Africa to Riverdale in the Western Cape Province. No type locality is listed. [1] Ghana
This is an active species that can often move relatively quickly—up to an estimated speed of 92 cm per second (3 feet per second). They are usually found on the ground, but have no trouble climbing or swimming. They are largely nocturnal, but are often seen basking in the early morning or late afternoon. However, Mallow et al. (2003) reported collecting a dozen specimens that were all active during the heat of the day. [3]
Most specimens are docile, seldom attempting to bite unless severely provoked. FitzSimons is quoted in Pitman (1938) [7] as saying that, in captivity, they "become so tame that you may allow them to creep, climb and slither round your neck and inside your garments." Others, however, are more temperamental. [3] [4]
When seriously disturbed, they will put on a "ferocious" threat display that includes coiling up, inflating the body (making the dark markings stand out), hissing and puffing loudly, flattening the anterior portion of the body, and striking frantically. They may also flatten the neck and move forward with the tongue extended, much like a small cobra. Striking is done with such vigor that small specimens may lift themselves off the ground entirely. [3] [4]
The diet consists mainly of toads, but it also includes frogs and small mammals. [8]
Females produce an average clutch of two dozen eggs that require a lengthy incubation period of approximately four months. The hatchlings are 10–12.5 cm (3.9–4.9 in) in total length and feed on tiny frogs and toads. [8]
Rhombic Night Adder bites can be serious and in at least one bite a child had to have a fasciotomy. [9] The few documented bites involved pain and minor swelling with minimal necrosis. These symptoms usually disappear within 2–3 days. There have been no modern well-documented cases to back up earlier claims of fatalities due to bites from this species. [4] Venom yield has varied from 20 to 30 mg to 300 mg, but the venom toxicity is low with LD50 values of 10.8, 14.6, >16.0 mg/kg IV and 15 mg/kg SC being reported. [3]
Echis carinatus, known as the saw-scaled viper, Indian saw-scaled viper, little Indian viper, and by other common names, is a viper species found in parts of the Middle East and Central Asia, and especially the Indian subcontinent. It is the smallest member of the "big four" Indian snakes that are responsible for causing the most snakebite cases and deaths, due to various factors including their frequent occurrence in highly populated regions, and their inconspicuous nature. Like all vipers, the species is venomous. Two subspecies are currently recognized, including the nominate subspecies described here.
Vipera berus, also known as the common European adder and the common European viper, is a species of venomous snake in the family Viperidae. The species is extremely widespread and can be found throughout much of Europe, and as far as East Asia. There are three recognised subspecies.
The Gaboon viper, also called the Gaboon adder, is a viper species found in the rainforests and savannas of sub-Saharan Africa. Like all other vipers, it is venomous. It is the largest member of the genus Bitis, and has the longest fangs of any venomous snake – up to 2 inches (5 cm) in length – and the highest venom yield of any snake. No subspecies are recognized.
Bitis nasicornis is a viper species belonging to the genus Bitis, part of a subfamily known as "puff-adders", found in the forests of West and Central Africa. This large viper is known for its striking coloration and prominent nasal "horns". No subspecies are currently recognized. Its common names include butterfly viper, rhinoceros viper, river jack and many more. Like all other vipers, it is venomous.
The puff adder is a highly venomous viper species found in savannahs and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rainforest regions. It is responsible for causing the most snakebite fatalities in Africa owing to various factors, such as its wide distribution, frequent occurrence in highly populated regions, and aggressive disposition. Like all other vipers, it is venomous. Two subspecies are currently recognized, including the nominate subspecies described here.
Atheris squamigera is a venomous viper species endemic to west and central Africa. No subspecies are currently recognized.
Causus is a genus of vipers found only in sub-Saharan Africa. It is a group considered to be among the most primitive members of the family Viperidae based on head scalation, oviparity, venom apparatus, and because they have round pupils. However, this is contradicted by recent molecular studies. Seven species are currently recognized. They are commonly known as night adders. Like all other vipers, they are venomous.
Echis is a genus of vipers found in the dry regions of Africa, the Middle East, India, Sri Lanka and Pakistan. They have a characteristic threat display, rubbing sections of their body together to produce a "sizzling" warning sound. The name Echis is the Latin transliteration of the Greek word for "viper" (ἔχις). Like all vipers, they are venomous. Their common name is "saw-scaled vipers" and they include some of the species responsible for causing the most snakebite cases and deaths in the world. Twelve species are currently recognized.
Vipera ammodytes, commonly known as horned viper, long-nosed viper, nose-horned viper, and sand viper, is a species of viper found in southern Europe, mainly northern Italy, the Balkans, and parts of Asia Minor. Like all other vipers, it is venomous. It is reputed to be the most dangerous of the European vipers due to its large size, long fangs and high venom toxicity. The specific name, ammodytes, is derived from the Greek words ammos, meaning "sand", and dutes, meaning "burrower" or "diver", despite its preference for rocky habitats. Five subspecies are currently recognized, including the nominate subspecies described here.
Vipera aspis is a viper species found in southwestern Europe. Its common names include asp, asp viper, European asp, and aspic viper, among others. Like all other vipers, it is venomous. Bites from this species can be more severe than from the European adder, V. berus; not only can they be very painful, but approximately 4% of all untreated bites are fatal. The specific epithet, aspis, is a Greek word that means "viper." Five subspecies are currently recognized, including the nominate subspecies described here.
Dasypeltis scabra, known as the common egg eater, egg-eating snake or rhombic egg eater, is a species of snake in the family Colubridae. It is endemic to Africa.
The berg adder is a venomous viper species endemic to mountainous regions in southern Africa. No subspecies are currently recognized.
The horned adder is a viper species. It is found in the arid region of southwest Africa, in Angola, Botswana, Namibia; South Africa, and Zimbabwe. It is easily distinguished by the presence of a single, large horn-like scale over each eye. No subspecies are currently recognized. Like all other vipers, it is venomous.
Bitis peringueyi, also known as the Peringuey's adder, Peringuey's desert adder or desert sidewinding adder, is a viper species found in Namibia and southern Angola. No subspecies are currently recognized.
Causus maculatus is viper species found mainly in West- and Central Africa. No subspecies are currently recognized. Common names include forest rhombic night adder, West African night adder and spotted night adder. Like all other vipers, it is venomous.
Causus bilineatus is a viper species endemic to south central Africa. No subspecies are currently recognized. Common names include lined night adder, two-lined night adder, and two-striped night adder. Like all other vipers, it is venomous.
Causus defilippii, commonly known as snouted night adder, is a species of snake in the family Viperidae. The species is endemic to East and Southern Africa. Although its venom is nonlethal to humans, it is still considered medically significant. There are no recognized subspecies.
Causus lichtensteinii is a viper species endemic to western, central, and eastern Africa. There are no subspecies that are recognized as being valid. Like all other vipers, the species is venomous.
Causus resimus is a viper species found in isolated populations distributed across tropical Africa. No subspecies are currently recognized. Like all other vipers, it is venomous.
The Persian horned viper, known as the Persian horned viper, false horned viper, and by other common names, is a species of vipers endemic to the Middle East and Asia. Like all other vipers, it is venomous.
